Back light device of liquid crystal device

A back light device of a liquid crystal display device, comprising:

• light sources;
• and
• a light guiding body made of a light transmitting material for guiding a light emitted from said light source so that the light is emitted towards a liquid crystal display panel,
• wherein at least one of said light sources is positioned just under a display area of a liquid crystal panel so as to be laid behind the back face of said light guiding body,
• wherein said light guiding body includes sections that intersect a circumferential end of the display area of the liquid crystal panel in the vicinity of the light sources and end faces where light from the light sources enters, either of said section and said face in the vicinity of each light source that is closer to the central portion of the display area being incident end face, one of said incident end face in the vicinity of the light sources where a quantity of incident light is larger being a first incident end face, the other incident end face where a quantity of incident light is smaller being a second incident end face,
• wherein said light guiding body includes a first optical portion for guiding an incident light from the first incident end face to the vicinity of the center so as to emit the light to the liquid crystal display panel and a second optical portion for guiding an incident light from the second incident end face to the vicinity of the portion so as to emit the light to the liquid crystal display panel,
• wherein a border between said first and second optical portions is set nearer to the second incident end face according to a ratio of the quantities of incident lights on each incident end face such that a difference in luminance between the first and second optical sections are eliminated.

A method of back lighting a liquid crystal display device, comprising the steps of:

• transmitting light emitted from light sources along a light guiding body towards a liquid crystal display panel, the light guiding body including a first section and a second section receiving different quantities of incident light from the light sources;
• guiding light, via a first optical section, from the first section to a central portion of said light guiding body and emitting light to the liquid crystal display panel;
• guiding light, via a second optical section, from the second section to the central portion of the light guiding body and emitting light to the liquid crystal display panel;
• and
• setting a border between said first and second optical sections according to a ratio of the quantities of incident light on each section such that a difference in luminance between the first and second optical sections are eliminated.